Mutants of Bacillus subtilis defective in various aspects of the cell cycle will be studied. Emphasis will be placed on growth and division studies of minicell-producing mutants and special strains which carry the minicell mutation in combination with other mutations that affect aspects of the cell cycle. Time lapse photographs of clones growing and dividing in specially constructed microscope cell chambers will be analyzed by computer for patterns of division and other parameters. Machine studies of growth and division using a computer interfaced to a celloscope will also be conducted. Purified minicells will be investigated in several manners. Attempts will be made to introduce genetic material into DNA-free minicells. Both phage and cell DNA systems will be explored. Other studies will probe the metabolism and enzymes found in minicells. Immunological studies of cell-cycle defective mutants of various kinds will also be pursued. Minicells will be included in the immunological studies which are aimed at identifying mutant defect. Finally, the search for new mutants will continue, as will the construction of new strains which bring together combinations of different mutations in the same cell for studies of their interactions.